Lexicographic Parsimony Pressure
نویسندگان
چکیده
We introduce a technique called lexicographic parsimony pressure, for controlling the significant growth of genetic programming trees during the course of an evolutionary computation run. Lexicographic parsimony pressure modifies selection to prefer smaller trees only when fitnesses are equal (or equal in rank). This technique is simple to implement and is not affected by specific differences in fitness values, but only by their relative ranking. In two experiments we show that lexicographic parsimony pressure reduces tree size while maintaining good fitness values, particularly when coupled with Kozastyle maximum tree depth limits.
منابع مشابه
Dynamic Maximum Tree Depth A Simple Technique for Avoiding Bloat in Tree-Based GP
We present a technique, designated as dynamic maximum tree depth, for avoiding excessive growth of tree-based GP individuals during the evolutionary process. This technique introduces a dynamic tree depth limit, very similar to the Koza-style strict limit except in two aspects: it is initially set with a low value; it is increased when needed to accommodate an individual that is deeper than the...
متن کاملImproving Generalization Ability of Genetic Programming: Comparative Study
In the field of empirical modeling using Genetic Programming (GP), it is important to evolve solution with good generalization ability. Generalization ability of GP solutions get affected by two important issues: bloat and over-fitting. Bloat is uncontrolled growth of code without any gain in fitness and important issue in GP. We surveyed and classified existing literature related to different ...
متن کاملEffects of Code Growth and Parsimony Pressure on Populations in Genetic Programming
Parsimony pressure, the explicit penalization of larger programs, has been increasingly used as a means of controlling code growth in genetic programming. However, in many cases parsimony pressure degrades the performance of the genetic program. In this paper we show that poor average results with parsimony pressure are a result of 'failed' populations that overshadow the results of populations...
متن کاملE ects of Code Growth and ParsimonyPressure on Populations in GeneticProgramming
Parsimony pressure, the explicit penalization of larger programs, has been increasingly used as a means of controlling code growth in genetic programming. However, in many cases parsimony pressure degrades the performance of the genetic program. In this paper we show that poor average results with parsimony pressure are a result of \failed" populations which overshadow the results of population...
متن کاملE ects of Code Growth and ParsimonyPressure on Populations in GeneticProgramming Terence
Parsimony pressure has been increasingly used as a means of controling code growth in genetic programming. However, several published papers have shown that in some cases its use can degrade the performance of the genetic program Koza, 1992, Nordin and Banzhaf, 1995]. In this paper we show that poor average results with parsimony pressure are a result of \failed" populations which overshadow th...
متن کامل